I updated my iPhone 5 - it took me 4 tries, since the server kept dropping out.
Overall, my feelings are mixed. I like the "control center" (ie. the Android-like panel get to things like the flashlight and turn wifi on/off). I like the look of the notification screen - but I liked the look of updated Yahoo weather app and it's the same sort of look. But I really dislike the icon colors. They seem garish and overtly colorful and I feel like my eyes hurt looking at them.... which is like my response to the iPhone 5C phone color choices as well. The dynamic wallpaper seems silly - I like the sort of parallax wallpaper on Android 4.0 and above, but this "move the phone moves the wallpaper" seems like something I'd have thought was cool when I was 12. I love the changes to Find iPhone and the increased sense of security around lost phones - they are a welcome improvement, and arguably something that iOS does a bit better than Android.
I like iTunes Radio - although it's basically Pandora. I think the new instagram-like phone filters are idiotic.. it seems bizarre to turn a high resolution modern camera in to a black and white camera from 100+ years ago, or an old Polaroid camera from 40 years ago. And I notice that I still can't delete - nor shove into a folder - that stupid Newsstand icon that I never use. Does Apple actually read user feedback?
Overall, I'm not thrilled, but appreciate the improved notification and control panels and I'll probably get used to the new OS over time. I have to say that in general, from the iPhone 5 onwards, I'm feeling like what I want and what Apple is actually doing are disconnected. The style of the iPhone 5C with it's bright colors, the iPhone 5S with "gold" as a color, and now the new icons in iOS7... they seem to be aiming to appeal to a group of people who aren't me. I'm more "old", "pedestrian" and "boring" and I'm sort of the anti-hipster and iOS7's style seems to be targeted at those guys who ride neon green single-speed bicycles with messenger bags over their shoulders.